Hydroponics system and method

ABSTRACT

A hydroponics system for growing plants in an aqueous nutrient solution and including troughs for conducting a predetermined level of nutrient solution, is disclosed. The solution is supplied to each trough by a branch pipe extending the length of the trough and including a plurality of outlets spaced at uniform intervals. The nutrients are thereby dispersed relatively evenly along the length of the trough. Each outlet has an associated aspirator or eductor whereby air is entrained by the solution issuing from the outlet thereby providing substantially uniform aeration of the nutrient solution. Each plant is supported by a receptacle having an open bottom through which the plant stem extends. The plant is held by resilient foam plastic inserts disposed between the plant stem and the receptacle wall.

0 United States Patent [151 3,660,933 Wong, Jr. 1 1 "May 9, 1970 [54]HYDROPONICS SYSTEM AND METHOD FORElGN PATENTS OR APPLICATIONS [72]Inventor: Edward Wong, Jr., Los Angeles, Calif. 1,054,671 1/1967 GreatBritain 1,390,943 1/1965 France [73] Assrgnee. Welngarten & WongEnterprises, Inc. 48.649 5/1929 Norway 22 F'led: Mar. 2 1970 1 l PrimaryExaminer-Robert E. Bagwill [21] Appl.N0.: 15,558 ArwmeyFraser&Bogucki 52mo. ..47/1.2, 239/428.5 [57] ABSTMCT [51] Int. Cl. ..A0lg 31/00 Ahydroponics system for growing plants in an aqueous 58 Fieldofsearch.239 423 5;47 1,z,17-13, nutrient solution and including troughs forconducting a 7 3 3 33 19 34 predetermined level of nutrient solution, isdisclosed. The solution is supplied to each trough by a branch pipeextending [56] Reerences Cited the length of the trough and including aplurality of outlets spaced at umfomt Intervals. The nutrients arethereby n- STATES PATENTS dispersed relatively evenly along the lengthof the trough. Each outlet has an associated aspirator or eductorwhereby air 2,241,699 5/1941 p is entrained by thesolution issuing fromthe outlet thereby 3,352,057 11/1967 Ferrandm /1- providingsubstantially uniform aeration of the nutrient solu- 2,188,875 1/1940Ellis ..47/l.2 tion. 2674338 g g Each plant is supported by a receptaclehaving an open bot- 9 l a es et a tom through which the plant stemextends. The plant is held 2189510 2/1940 Swaney by resilient foamplastic inserts disposed between the plant R2 1 ,820 6/1941 Munsell..47/1.2 stem and the receptacle wan 2,316,832 4/1943 Aghnides.......239/428.5 3,305,968 2/1967 13 Claims, 5 Drawing Figures Dosedla et a1...47/1 .2

MTENT'EDMY 91972 SHEET 1 OF 2 NUTRIENTS HGPH INV/LJ) I 01-: EDWARDWONG,JR.

F7241 1a? my Poauclo ATTORNEYS WETEDW '9 1972 SHEET 2 BF 2 lNVliN ulEDWARD wows, JR.

Franc-2 mm Uouuuq AT TORNEYS BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates generally to hydroponics andparticularly to systems and methods for growing plants hydroponically ona commercial scale and wherein an aerated, aqueous nutrient solution isefficiently and substantially unifonnly distributed to all of the plantsbeing grown.

2. Description of the Prior Art One technique for the hydroponic growthof plants on a large scale makes use of a series of elongated troughsthrough which is circulated a nutrient solution containing the necessarygrowth-promoting substances. In these existing systems, the nutrientsolution normally enters each trough at one end and is discharged at theother end with the result that all or most of the nutrients tend to beconsumed by the plants nearest the end at which the solution isintroduced to the detriment of the plants toward the discharge end.Often, there will be plainly evident a marked, steady decrease in plantsize and yield from the inlet end to the discharge end of the trough.

Among the various factors substantially affecting plant growth is theamount of air supplied to the plant roots. Many existing hydroponicsystems depend upon what little air is normally present in the nutrientsolution together with the relatively stagnate air present in the troughabove the level of the nutrient solution. Attempts to supplement the airin the nutrient solution have chiefly comprised various schemes forbubbling air under pressure into the nutrient solution. However, theamount of air required for a large hydroponics farm may necessitate theuse of several high capacity motors and compressors and additionallythese must be maintained in operation at all times. It will be obviousthat the expense involved in the installation and maintenance of thismachinery is considerable. Furthermore, in many of these systems the airis not supplied to all of the plants uniformly with the result thatnonuniform plant growth takes place with an attendant decrease inoverall yield.

In accordance with one of the broad aspects of the present invention, alarge scale, commercial hydroponics system is provided for bothsupplying the nutrient solution and aerating the solution substantiallyuniformly along the entire length of the trough. Uniform and optimumgrowth and yield are thereby promoted.

Pursuant to one specific embodiment of the invention there is provided aseries of troughs each of which is adapted to carry a predeterminedlevel of nutrient solution circulated to and from a main reservoir bysuitable pumping and conduit means. Each trough is supplied withnutrient solution by a branch pipe running substantially the entirelength of the trough and disposed above the nutrient solution level. Thebranch pipe includes a plurality of outlets uniformly spaced along thelength of the pipe. Associated with each outlet is an eductor wherebyair is entrained by the stream of nutrient solution issuing atrelatively high velocity from the outlet. The air thus entrained issubstantially completely and uniformly mixed with the solution moving inthe trough. Furthennore, the stream of nutrient solution impinging uponthe surface of the solution causes agitation and mixing thereof tofurther increase the level of aeration and insuring that uniformity ofthe aerated nutrient solution is maintained along the entire length ofthe trough.

Another aspect of the invention relates to the support means for holdingthe growing plants so that the roots thereof are maintained immersed inthe nutrient solution in the trough. The support means for each plantincludes a tapered receptacle such as a plant pot having an open bottomthrough which the plant stern extends. The stem is held againsttransverse movement by a plurality of foam plastic inserts placedbetween the wall of the receptacle and the stem and which yield as' thediameter of the stem increases during growth of the plant. The supportmeans further includes a platform across the top of the trough andhaving one or more longitudinal rows of apertures for receiving theplant receptacles. According to one specific configuration, two rows ofplants are supported by the platform with the branch pipe for supplyingthe nutrient solution resting on the platform between the plant rows.The platform has a central row of apertures through which the branchpipe outlet nozzles and eductors extend downwardly into the trough.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects, advantages andfeatures of the invention will become evident from a reading of theensuing description of the preferred embodiments which makes referenceto the accompanying drawings, in which:

FIG. I is a plan view of a portion of a trough-type hydroponics systemincorporating features of the present invention;

FIG. 2 is a perspective view of a portion of one of the troughs of thehydroponics system of FIG. 1;

FIG. 3 is a longitudinal cross section in elevation of one of thetroughs of the system of FIG. 1 as seen along the plane 3- FIG. 4 is aperspective view of one of the troughs of the system of FIG. 1 showingthe discharge 'end and nutrient solution level controlling means; and

FIG. 5 is a cross section view in elevation of a plant receptacleaccording to another aspect of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to the drawings,there is shown a hydroponics system which includes generally a reservoir10 for holding a large quantity of aqueous nutrient solution, a pump 12and a common supply pipe 14 coupling the reservoir 10, the pump 12 and aseries of troughs I6, l7, l8 and 19. Any number of troughs may beprovided; only four are shown by way of example. Further, the troughsmay be divided into parallel-connected groups, each group being suppliedby an individual pump, such as the pump 12, and a separate supply pipe,such as the pipe 14.

Dissolvable nutrients, in the appropriate quantity and proportions, areadded as necessary to the reservoir 10 either manually or automatically.The nutrients required for the satisfactory promotion of growth, theirproportioning, and so forth are all well known in the art and will notbe discussed as they do not form any pertinent part of the presentinvention.

The troughs 16-19 are arranged in spaced, parallel relation and areindividually supplied with nutrient solution by branch pipes 20, 21, 22and 23, respectively, coupled to the common supply pipe 14. Each trough16-19 includes an outlet end 24, 25, 26 and 27, respectively, fordischarging the nutrient solution from the trough for return to thereservoir 10 via a conduit 28. The conduit 28 may simply take the fonnof an open or covered channel or ditch or closed conduit gently slopedso as to provide return flow under the influence of gravity to thereservoir 10.

Portions of trough 16 are shown in greater detail in FIGS. 2, 3 and 4.It is to be understood that the trough 16 is typical of the troughs ofthe system.

The trough I6 comprises a pair of parallel, spaced vertical walls 34 and36 which may be fabricated of any suitable, durable material, forexample, wood, steel, concrete or the like. The side walls 34 and 36have horizontal, coplanar upper edges 38 and 40, respectively. Suspendedbetween the side walls 34 and 36 and supported by the upper edgesthereof and the ground intermediate the side walls, is an open channel42 running the length of the trough and within which the nutrientsolution flows. In one practical form of the invention, the channel 42is heavy polyethylene sheet, although it will be apparent othermaterials resistant to attack by the nutrient solution may be utilized.

Spanning the upper edges 38 and 40 of the side walls 34 and 36 is aplatform 46 which may be conveniently fabricated in sections such as46a, 46b and 46c and constructed of hardboard, wood, or the like. Theplatform 46 serves several purposes: it firmly secures the upper edgesof the polyethylene sheet 42 and forms a support for both the plants tobe grown and the branch pipe 20 feeding the trough 16.

The platform 46 has a pair of longitudinally extending, parallel rows ofcircular openings 48 for receiving plant receptacles 50. As best shownin FIG. 5, each receptacle 50 has a tapering main section 52 dependingfrom an outwardly extending flange 54 at the upper end. The outerdiameter of the flange 54 is somewhat larger than the opening 48 so thatthe receptacle 50 is suspended thereby. Each receptacle 50 furtherincludes a bottom 56 having an opening 58 through which the plant stemextends.

The plants to be grown by the system under discussion are initiallycultivated from the seed hydroponically or in soil for a short period oftime. The young seedlings, which are now large enough so that theirroots will reach and become immersed in the nutrient solution, aretransferred to the receptacles 50 where their remaining growth takesplace. Each plant is held securely within the receptacle 50 by at leasttwo foam plastic inserts 60, the inner and outer extremities of whichengage the plant stem and receptacle wall, respectively. For additionallateral support as the plant becomes larger, pea gravel may be added toeach receptacle 50 above the plastic inserts 60. As the plant grows andthe stem diameter increases, the plastic inserts 60 resiliently yield tocompensate for the diametric enlargement without damage to the plant orthe necessity of having to replace the inserts with ones of differentsize to accommodate the larger plant stem.

The branch pipe 20 is preferably positioned so as to rest on theplatform 46 along approximately the longitudinal center line thereof.Spaced at uniform intervals along the branch pipe 20 and projectingdownwardly therefrom through apertures 62 formed in the platform 46, area series of nozzles 64 for discharging streams of nutrient solution intothe trough below. According to one practical example of the invention,each branch pipe is about 80 feet in length with outlet nozzles spacedevery 8 feet. The branch pipe is made of 1% inch PVC (polyvinylchloride) plastic piping which is relatively inexpensive and resistscorrosion. Further, by laying the branch pipe on top of the platform 46,installation and maintenance are greatly simplified.

Each outlet nozzle 64 carries an aspirator or eductor 66 for introducingair into the stream flowing from the discharge nozzle. Each eductor 66has a reduced diameter section 68 and an air inlet 70 upstream thereof.As the nutrient solution discharges from the nozzle 64 at a relativelyhigh velocity as a result of the pressurization produced by the pump 12,a reduced pressure zone is formed within the constricted section 68 inaccordance with well known principles of fluid dynamics and air isthereby drawn through the inlet 70 and entrained by the solution. Inthis fashion, the nutrient solution is aerated uniformly along theentire length of the trough. The nutrient solution streams issuing fromthe nozzles 64 furthermore agitate and thoroughly mix the aeratedsolution in the trough to insure substantially complete uniformity ofnutrient concentration and air content throughout all portions of thetrough.

The level of the nutrient solution within the trough is typicallymaintained at about five inches. This level is controlled by an overflowgate arrangement shown in FIG. 4. A gate 74 is carried by verticallyextending slotted guide members 76 and 78 attached to the rearextremities of the side walls 34 and 36. The gate 74 is fixed at theappropriate vertical position within the slotted members 76 and 78 toestablish the desired solution level.

What is claimed is:

1. In an hydroponic system, the combination comprising:

at least one trough;

a reservoir for holding a supply of aqueous nutrient solution; and

means connecting said reservoir and said trough for both supplying saidnutrient solution to said trough and aerating said solutionsubstantially uniformly along the length of said trough.

2. In an hydroponic system, the combination comprising:

at least one trough;

a reservoir for holding a supply of aqueous nutrient solution; and

means connecting said reservoir and said trough for circulating saidnutrient solution to and from said trough and aerating said solutionsupplied to said trough substantially uniformly along the length of saidtrough.

3. In an hydroponic system, the combination comprising:

at least one trough for carrying a predetermined level of aqueousnutrient solution;

a reservoir for holding a supply of said solution;

means coupled to said reservoir and disposed above said nutrientsolution level for supplying said trough with said nutrient solutionsubstantially uniformly along the length of said trough and includingmeans for aerating said solution as said solution is supplied to saidtrough.

4. The combination defined in claim 3 in which:

said solution supply means includes a plurality of outlets substantiallyevenly spaced along the length of said trough and said aerating meanscomprises an eductor coupled to each of said outlets.

5. In an hydroponic system, the combination comprising:

a reservoir for holding a supply of aqueous nutrient solution;

a plurality of elongated troughs, each trough adapted to support aplurality of plants to be nourished by said solution and further adaptedto carry a predetermined level of said solution;

means for conducting solution under pressure from said reservoir to saidtroughs, said conducting means including branch pipes for supplyingsolution to individual troughs, each of said branch pipes supplying anindividual trough and disposed above the level of said solution and saidtrough including a plurality of outlets spaced substantially uniformlyalong the length thereof;

eductor means operatively associated with each of said outlets foraerating the solution issuing from said outlet; and,

conduit means communicating with said troughs for returning saidsolution to said reservoir.

6. A combination, as defined in claim 5, in which:

each trough includes a pair of spaced, parallel sidewalls having upperedges lying substantially in a common horizontal plane;

and which combination further includes:

plant-carrying means supported by said upper edges, said branch piperesting on said plant carrying means, said outlets extending throughspaced apertures formed in said carrying means.

7. The combination, as defined in claim 5, in which:

each of said troughs includes a discharge end and overflow gate means atsaid discharge end positioned for predetermining the level of saidsolution in said trough, said return conduit being adjacent saiddischarge end.

8. The combination, as defined in claim 6, in which:

said plant-carrying means comprises a platform extending the length ofsaid trough and having at least one longitudinally-extending row ofopenings for receiving plantholding receptacles.

9. The combination, as defined in claim 5, in which:

each trough includes a pair of spaced, parallel sidewalls and meansbetween said sidewalls defining an open channel for conducting saidsolution.

10. The combination, as defined in claim 5, in which:

said channel-defining means comprises a polyethylene sheet.

11. A method of growing plants hydroponically in an elongated trough,comprising the steps of:

supplying an aqueous nutrient solution to said trough substantiallyuniformly along the entire length of said trough ing said solution beingsupplied at each of said points. 13. A method of growing plantshydroponically, as defined in claim 12, in which:

said nutrient solution is supplied to said trough from above the levelof the solution in said trough.

ll a l I II

1. In an hydroponic system, the combination comprising: at least onetrough; a reservoir for holding a supply of aqueous nutrient solution;and means connecting said reservoir and said trough for both supplyingsaid nutrient solution to said trough and aerating said solutionsubstantially uniformly along the length of said trough.
 2. In anhydroponic system, the combination comprising: at least one trough; areservoir for holding a supply of aqueous nutrient solution; and meansconnecting said reservoir and said trough for circulating said nutrientsolution to and from said trough and aerating said solution supplied tosaid trough substantially uniformly along the length of said trough. 3.In an hydroponic system, the combination comprising: at least one troughfor carrying a predetermined level of aqueous nutrient solution; areservoir for holding a supply of said solution; means coupled to saidreservoir and disposed above said nutrient solution level for supplyingsaid trough with said nutrient solution substantially uniformly alongthe length of said trough and including means for aerating said solutionas said solution is supplied to said trough.
 4. The combination definedin claim 3 in which: said solution supply means includes a plurality ofoutlets substantially evenly spaced along the length of said trough andsaid aerating means comprises an eductor coupled to each of saidoutlets.
 5. In an hydroponic system, the combination comprising: areservoir for holding a supply of aqueous nutrient solution; a pluralityof elongated troughs, each trough adapted to support a plurality ofplants to be nourished by said solution and further adapted to carry apredetermined level of said solution; means for conducting solutionunder pressure from said reservoir to said troughs, said conductingmeans including branch pipes for supplying solution to individualtroughs, each of said branch pipes supplying an individual trough anddisposed above the level of said solution and said trough including aplurality of outlets spaced substantially uniformly along the lengththereof; eductor means operatively associated with each of said outletsfor aerating the solution issuing from said outlet; and, conduit meanscommunicating with said troughs for returning said solution to saidreservoir.
 6. A combination, as defined in claim 5, in which: eachtrough includes a pair of spaced, parallel sidewalls having upper edgeslying substantially in a common horizontal plane; and which combinationfurther includes: plant-carrying means supported by said upper edges,said branch pipe resting on said plant carrying means, said outletsextending through spaced apertures formed in said carrying means.
 7. Thecombination, as defined in claim 5, in which: each of said troughsincludes a discharge end and overflow gate means at said discharge endpositioned for predetermining the level of said solution in said trough,said return conduit being adjacent said discharge end.
 8. Thecombination, as defined in claim 6, in which: said plant-carrying meanscomprises a platform extending the length of said trough and having atleast one longitudinally-extending row of openings for receivingplant-holding receptacles.
 9. The combination, as defined in claim 5, inwhich: each trough includes a pair of spaced, parallel sidewalls andmeans between said sidewalls defining an open channel for conductingsaid solution.
 10. The combination, as defined in claim 5, in which:said channel-defining means comprises a polyethylene sheet.
 11. A methodof growing plants hydroponically in an elongated trough, comprising thesteps of: supplying an aqueous nutrient solution to said troughsubstantially uniformly along the entire length of said trough andsimultaneously aerating said solution during the supplying thereof. 12.A method of growing plants hydroponically in an elongated trough,comprising the steps of: supplying an aqueous nutrient solution to saidtrough at a plurality of points spaced substantially uniformly along theentire length of said trough and simultaneously aerating said solutionbeing supplied at each of said points.
 13. A method of growing plantshydroponically, as defined in claim 12, in which: said nutrient solutionis supplied to said trough from above the level of the solution in saidtrough.